Mortar元法(mortar element method,MEM)是一种新型区域分解算法,它允许将求解区域分解为多个子域,在各个区域以最适合子域特征的方式离散。在各个区域的交界面上,边界节点不要求逐点匹配,而是通过建立加权积分形式的Mortar条件使得交...Mortar元法(mortar element method,MEM)是一种新型区域分解算法,它允许将求解区域分解为多个子域,在各个区域以最适合子域特征的方式离散。在各个区域的交界面上,边界节点不要求逐点匹配,而是通过建立加权积分形式的Mortar条件使得交界面上的传递条件在分布意义上满足。Mortar有限元法(mortar finite element method,MFEM)将MEM和有限元法(finite element method,FEM)相结合,在各区域中分别使用FEM网格离散,区域的交界面上通过施加Mortar条件实现区域间的自由度连续。该文阐述了非重叠Mortar有限单元法(non-overlapping MFEM,NO-MFEM)的基本原理,介绍了NO-MFEM的程序实现过程,使用NO-MFEM对2维静磁场问题和3维静电场问题进行了计算,并与FEM模型结果进行对比,验证了该文方法的有效性。将NO-MFEM应用于电磁分析,丰富了电磁场数值计算理论,为运动涡流问题和大规模问题的分析提供了新的选择。展开更多
In this paper, we introduce a z-axis quartz gyroscope using a double-H tuning fork, which has a high sensitivity. However, it also causes a large mechanical quadrature error. The laser trimming method is used to suppr...In this paper, we introduce a z-axis quartz gyroscope using a double-H tuning fork, which has a high sensitivity. However, it also causes a large mechanical quadrature error. The laser trimming method is used to suppress this error at quartz level. The trimming law is obtained through the finite element method （FEM）. A femtosecond laser processing system is used to trim the gold balancing masses on the beams, and experimental results are basically consistent with the simulated ones. The mechanical quadrature error is suppressed by 96%, from 26.3° s-1 to 1.1° s-1. Nonlinearity changes from 1.48% to 0.30%, angular random walk （ARW） is reduced from 2.19° h-1/2 to 1.42° h-1/2, and bias instability is improved by a factor of 7.7, from 197.6° h-1 to 25.4° h-1.展开更多
文摘Mortar元法(mortar element method,MEM)是一种新型区域分解算法,它允许将求解区域分解为多个子域,在各个区域以最适合子域特征的方式离散。在各个区域的交界面上,边界节点不要求逐点匹配,而是通过建立加权积分形式的Mortar条件使得交界面上的传递条件在分布意义上满足。Mortar有限元法(mortar finite element method,MFEM)将MEM和有限元法(finite element method,FEM)相结合,在各区域中分别使用FEM网格离散,区域的交界面上通过施加Mortar条件实现区域间的自由度连续。该文阐述了非重叠Mortar有限单元法(non-overlapping MFEM,NO-MFEM)的基本原理,介绍了NO-MFEM的程序实现过程,使用NO-MFEM对2维静磁场问题和3维静电场问题进行了计算,并与FEM模型结果进行对比,验证了该文方法的有效性。将NO-MFEM应用于电磁分析,丰富了电磁场数值计算理论,为运动涡流问题和大规模问题的分析提供了新的选择。
基金Project supported by the National Natural Science Foundation of China(Grant No.61027007)
文摘In this paper, we introduce a z-axis quartz gyroscope using a double-H tuning fork, which has a high sensitivity. However, it also causes a large mechanical quadrature error. The laser trimming method is used to suppress this error at quartz level. The trimming law is obtained through the finite element method （FEM）. A femtosecond laser processing system is used to trim the gold balancing masses on the beams, and experimental results are basically consistent with the simulated ones. The mechanical quadrature error is suppressed by 96%, from 26.3° s-1 to 1.1° s-1. Nonlinearity changes from 1.48% to 0.30%, angular random walk （ARW） is reduced from 2.19° h-1/2 to 1.42° h-1/2, and bias instability is improved by a factor of 7.7, from 197.6° h-1 to 25.4° h-1.
